The disclosure generally relates to the auto white balance (AWB) calibration and, more particularly, to a method for generating a pixel filtering boundary required by the AWB calibration.
The AWB calibration greatly affects the image quality, and is thus widely employed in many applications, such as digital cameras, smart phones, tablet computers, surveillance systems, or the like.
The pixel data is typically represented in the form of RGB format in general imaging system, but the conventional AWB calibration has to convert the pixel data to the Cb-Cr color space so that the pixel data can be filtered and compensated during the AWB calibration. Afterwards, compensated pixel data would be converted from the G/B-G/R color space to the R gain and B gain to be applied in the imaging system.
In other words, the conventional AWB calibration needs to convert the pixel data between the G/B-G/R color space and the Cb-Cr color space. Converting pixel data between the G/B-G/R color space and Cb-Cr color space not only requires extra computations, but also easily causes color error in the resulting image.